Until now, a terminal strip has been used as a separate supply terminal for supplying power via a busbar system in the case of power breakers having cage clamp spring terminal connections. The power is supplied by lines from the terminal strip to a busbar system to which the individual power breakers or switching devices are connected by way of flexible lines. If, for example, four outgoing branches are supplied with power by a busbar system such as this, and four further outgoing branches are to be added in parallel with the same power supply, this is only possible by the power in the busbar being fed via the terminals of the fourth power breaker.